Modeling a zombie epidemic using SIR
https://www108.lamp.le.ac.uk/ojs1/index.php/pst/article/view/889
https://www108.lamp.le.ac.uk/ojs1/index.php/pst/article/view/885
‘Another Zombie Epidemic’ is a revised version of their first paper, ‘A Zombie Epidemic’, which builds on the SIR model to create their desired model for a zombie epidemic. This new model includes more parameters and is more dynamic. The first model placed a time limit of 100 days and did not factor in birth and death rates.
Factors that changed from their first paper:
– The infection probability p is now variable according to the model’s environment.
– Humans are now able to kill zombies.
– Rate of births and deaths are taken into account.
Their model is named SZD where “S is the population that is susceptible to the zombie virus, Z is the number of zombies, and D is the number of people that have died”.
dS/dt is given by population growth rate – infection rate.
dZ/dt is given by infection rate – zombie death rate – zombie kill rate.
dD/dt is given by zombie death rate + zombie kill rate.
Population growth rate: Half the population is assumed to be fertile at any time. One baby is born every 3 years.
Infection rate is the fraction of population that are infected or have turned into zombies.
Zombie death rate: a zombie’s lifespan is one year.
Zombie kill rate: Each day, every person has a probability of 0.1 to succeed in killing a zombie.
By running a computational model with these initial parameters, the following graph is generated:
These results show that with the suggested environment, it is possible for the humanity to overcome a zombie epidemic!